Detection of Anti-HLA Class I but Not C1q-Fixing Donor-Specific Antibodies before Kidney Transplantation Predicts Early Graft Loss
Nephrology, Hospital del Mar, Barcelona, Spain
Immunology and Nephrology, Hospital Insular, Las Palmas, Spain
Immunology, Laboratori Referencia Catalunya, Hospital del Mar, Barcelonaq, Spain
Meeting: 2013 American Transplant Congress
Abstract number: 352
Anti-HLA donor-specific antibodies(DSA) identified by Luminex are questioned for excess in sensitivity and lack of prediction of clinical events after kidney transplantation(KT). We performed a retrospective study to evaluate if specific types of preformed DSA (class I or II or C1q–fixing ones) have impact on graft survival.
Methods: KT performed 2006-2011 across a negative mixed-lympocytes CDC-crossmatch were included(n=355). Anti-HLA antibodies were tested using Luminex Lifecodes LifeScreen and LSA Class I/II assays. One Lambda commercial kits confirmed DSA before detection of C1q fixing antibodies with One Lambda’s Single Antigens Beads and C1q screen kits.
Results: 66 patients with positive screening were tested for DSA; 28 pretransplant DSA+ KT with MFI>2000 were tested for C1q fixation. They were 75% female, 64.3% reKT with a high rate of biopsy-proven acute rejection(35.7%) and acute antibody-mediated-rejection(AMR=25%). Early graft loss (<3 months post-KT) was 14.3% and global loss=21.4% at 30 months follow-up. Renal function for surviving grafts was good (median last SCr=1.27 mg/dl).
DSA were C1q+ in 15 patients and C1q- in 13 without significant differences in demographics, acute rejection(33.3 vs 46.2%), acute AMR(26.7% vs 30.8%), graft loss(20 vs 23.1%) or renal function at follow-up. Immunodominant DSAC1q+ had higher MFI than C1q-DSA (12190+7141vs5630+4747, p=0.008). Postransplant monitoring showed C1q+ DSA class-II persisted postKT more frequently than C1q- DSA class-II (60 vs 30.8%) without statistical significance.
Ten patients had anti-HLA DSA class-I with/without class-II and 18 patients only class-II. Patients with class-I suffered more AMR than class-II (50 vs 16.7%, p=0.06). They had significant worse graft survival over time (p=0.01); four early graft losses (<3mo postKT) occurred in DSA-I group. Capacitiy of DSA I to fix C1q did not correlate to AMR (50% in C1q+DSAI and C1q-DSAI) or graft loss (C1q+ 50% vs. C1q- 33%). Postransplant persistence of DSA class-II was more frequent than of DSA-I (66.7 vs 16.7%,p=0.06).
Conclusion: C1q testing in pretransplant sera with DSA was unable to predict antibody-mediated rejection or graft loss, but the presence of DSA class-I compared to class-II did. PreKT DSA-I C1q- can mediate AMR and graft loss.
To cite this abstract in AMA style:
Crespo M, Torío A, Mas V, Perez-Saez M, Mir M, Faura A, Checa M, Pascual J. Detection of Anti-HLA Class I but Not C1q-Fixing Donor-Specific Antibodies before Kidney Transplantation Predicts Early Graft Loss [abstract]. Am J Transplant. 2013; 13 (suppl 5). https://atcmeetingabstracts.com/abstract/detection-of-anti-hla-class-i-but-not-c1q-fixing-donor-specific-antibodies-before-kidney-transplantation-predicts-early-graft-loss/. Accessed May 14, 2025.« Back to 2013 American Transplant Congress